JPH0219213A - Stretch packing machine - Google Patents

Abstract

PURPOSE:To perform packing at a film delivery speed reduced in speed irregularity by making the shape of the rotary surface of the wheel to be driven on the side of a turntable approximately similar to the cross-sectional shape of the rotary plane of a cargo to be packed. CONSTITUTION:As the sprockets 42, 43, 44, 45 mounted on a rotary wheel 40 so as to be suppressed in rotation, the min. opens are used from the aspect of transmission power or the shape dimension of a chain to be used and arranged in a shape approximately similar to the shape dimension of the rotary surface of a cargo 33 to be packed to be mounted to a turntable 30 so as to become the same and similar to the state and position wherein the cargo 30 to be packed is placed on the turntable 30. When the rotary wheel 40 is driven by a rotation transmission mechanism 50 through a chain 46 and a chain tensioner 47, the turntable 30 performs no uniform rotation and the side surface of the cargo 33 to be packed generates uniform motion and no unreasonableness is generated in stretching a film.

Description

[Detailed description of the invention] 【Technical field】

TECHNICAL FIELD The present invention relates to a packaging machine, and more particularly, to a stretch packaging machine that wraps a packaged item by wrapping it around a stretched plastic stretch film.

[Prior art]

The present applicant has provided a means for wrapping cargo stacked on a pallet using a stretch film that is stretched by pulling, in ``Japanese Patent Publication No. 54-43957 Pallet Wrapping Apparatus.'' Briefly, as shown in FIG. It is connected to a packaging machine that wraps a film around a package by fixing the film to the package and rotating the turntable 2 (in the example shown in FIG. 2, clockwise when looking down from above). Although this packaging machine is in useful use today, it has developed drawbacks over time. The present invention eliminates this drawback and provides a stretch wrapping machine that is more useful than ever. The drawback is that the package 13 shown in FIG. 2 is a square package placed on the rotating table 2. Since the rotary table 2 is driven by the electric motor 4 via the rotation transmission mechanism of the gear 3, the circumferential speed of nine rotations is generally constant. Therefore, the package 13 is also rotated at a constant speed. In this case, as shown in Fig. 3, if the packaged object 13 is a regular square as shown in Fig. 9 in the plan view of the packaging machine, the corners of the square are The distance from center C is about 1.4 times longer. Therefore, there is a 1.4 times difference in the speed at which the film 11 is fed out when part a is rolled as shown in Figure 4 and when part b is rolled as shown in Figure 5. It will be faster if it is shown. Due to the influence of inertia and friction of the rotating parts, the film 11 cannot be rapidly stretched with the same stretching force due to this change in speed. Therefore, if an attempt is made to wrap the film firmly and economically by stretching the film strongly, the film tends to break at the position shown in FIG. Economically, today's films can be stretched by about 300%, and the greater the stretching, the greater the breaking strength of the film. To compensate for this phenomenon and to greatly stretch and package films, basically two means have been proposed to date. One of them is an accumulator 20 as shown in FIG.
The purpose is to buffer the film that is rapidly pulled. As shown in the figure, the rocking piece 23 allows the rolls 21 and 22 to rotate.
The swinging piece 23 is mounted on the shaft 2 by means of a spring 24 or the like.
Torque is applied in a clockwise direction around 5. The film is passed between rolls 21, 22 and wrapped around the package 13 as shown. When the film is subjected to sudden tension, the swinging piece 23 rotates counterclockwise to buffer the film. Such a means is shown as a 90 accumulator in FIG. 2 of ``Japanese Unexamined Patent Publication No. 56-84907 Packaging Method and Apparatus Therefor.'' Other means include the above-mentioned "Japanese Unexamined Patent Publication No. 56-64907 Packaging Method and Apparatus" and "Japanese Patent No. 1266739
40682 Packaging method and device” “Patent No. 136348
2 Patent Publication No. 61-27254 Packaging Method and Apparatus" and "Japanese Patent Publication No. 83-22/317 Multistage Pre-Stretch Wrapping Apparatus and Packaging Apparatus", etc., and are basically As in FIG. 7, roll 26.2
In a pre-stretching device consisting of 7 (Japanese Patent Application Laid-Open No. 63-22317 multi-stage pre-stretching packaging device and three rolls in this packaging device), the downstream roll 26 is rotated faster than the upstream roll 27, and the film is pre-stretched between these rolls. It is stretched and wrapped around the package 13 relatively softly. By doing this, the nine wraps of film tend to shrink over the course of two hours, and the film can be prevented from breaking while providing a strong wrapping force. However, both the method using an accumulator and the method using pre-stretching basically cannot avoid the adverse effects caused by uneven film unwinding speeds for non-circular packages such as squares.

[Purpose of the invention]

The present invention was invented with the aim of eliminating the above-mentioned drawbacks of conventional stretch packaging machines and allowing packaging to be performed at a uniform film feed-out speed.

[Summary of the invention]

As shown in FIG. 1, a nine-turn turntable 30 is attached to the belt. When transmitting rotation from a prime mover 31 (usually an electric motor) via a rotation transmission mechanism 50 such as a chain or lobe, 9
The shape of the driven vehicle 32 of the rotation transmission mechanism 50 is the same as that of the packaged cargo 3.
The shape is approximately similar to the shape on the rotating surface of No. 3 (the plane parallel to the plane on which the packaged package 33 is placed on the rotation stage of the packaged package), and when the prime mover 31 rotates at a constant speed, the outer surface of the packaged package 33 also rotates. It is designed to move at a constant speed.

【Example】

FIG. 8 shows a driven vehicle 3 in a preferred embodiment of the present invention.
2 shows the configuration of No. 2 and the rotation transmission mechanism 50. FIG. 8 shows the driven wheel 32 and the transmission mechanism when a chain transmission mechanism is used as the rotation transmission mechanism 50 used in the stretch wrapping machine of the present invention shown in FIG. In this case, the prime mover 31. The motive vehicle 34 is a commonly known commercially available product. That is, the prime mover 31 is a three-phase induction motor, for example, and the prime mover 34 is an ordinary circular chain sprocket. To explain FIG. 8, 40 is a rotating wheel, and in the center is a rotating shaft (not shown) that transmits rotation to the rotating turntable 30.
A hole 41 is provided for mounting the. 42, 43, 44, 45 are small-diameter circular sprockets that are mounted on the two-turn wheel 40 so as to be prevented from rotating. It is preferable that the sprockets 42, 43, 44, and 45 have a diameter as small as possible, but it is preferable to use the smallest sprocket in view of the power to be transmitted and the shape and dimensions of the chain used. Furthermore, the arrangement of the sprockets 42, 43, 44, and 45 is approximately similar to the cross-sectional shape of the packaged cargo 33 on the rotating surface, and the sprockets 42, 43, 44, and 45 are arranged in a similar shape to the state and position of the packaged cargo 33 placed on the rotating table 30. As shown in Figure 1, the rotating table 3
Set it to 0. That is, when the cross-sectional shape is square, the arrangement of the sprockets 42, 43, 44, and 45 is also square. If the above cross-sectional shape is rectangular, sprocket 42.4
The arrays 3, 44, and 45 are also rectangular, and the rectangles are arranged in a similar shape to the packages to be packaged and mounted on the two-turn turntable 30. If the cross section of the packaged cargo 33 is elliptical, a large number of sprockets can be used and arranged in an elliptical shape on the nine-rotation wheel 4o, or an elliptical sprocket can be manufactured and used. In FIG. 8, 46 is a chain, and 47 is a chain tensioner. In the embodiment shown in FIG.
．． The chain tensioner 47 is essential because the lengths of engagement between the chains 43, 44, and 45 are somewhat different. Such a rotation transmission mechanism 50 (drive mechanism) shown in FIG.
It is easily understood from the fact that the speed of the chain 46 is constant that when driven by the chain 46, the rotating turntable 30 shown in FIG. I could do it. The rotation transmission mechanism 50 includes a gear transmission mechanism (in this case, it is necessary to appropriately insert an idler wheel between the driven wheel 32 and the motive wheel 34), a belt transmission mechanism, a lobe transmission mechanism,
A conventionally known transmission mechanism such as the above can be used. According to the present invention, the purpose of wrapping the film around the packaged cargo 33 at a substantially constant speed on the surface to be wrapped can be achieved very economically, so that when the film is stretched, it is possible to (Compared to conventional methods, the film does not break even if it is stretched more than before, and the cost of the film can be saved. Naturally, even when a pre-stretching device is provided between the film 11 and the packaged item 33, the present invention can wrap the film around the packaged item 33 better than a conventional wrapping machine equipped with such a device.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the present invention. FIG. 2 is a perspective view of the conventional one. FIG. 3 is a plan view of the conventional one. FIGS. 4 and 5 are explanatory diagrams showing a state in which a film is wound in a conventional packaging machine. FIGS. 6 and 7 are explanatory diagrams showing other conventional examples. FIG. 8 is a perspective view showing one embodiment of the rotation transmission mechanism of the present invention. next. 2 is a rotating table, 3 is a gear, and 4 is an electric motor. 6 is the roll stand, 7 is the side body. 11 is a film, 13 is a package. 20 is an accumulator. 21.22 is a roll. 23 is a swing piece, and 24 is a spring. 25 is the axis. 26.27 is a roll. 30 is a rotating turntable. 31 is the prime mover. 32 is a driven vehicle. 33 is packaged baggage. 34 is the prime mover. 40 is a rotating wheel. 41 is a hole. 42.43,44°46 is a chain. 47 is the chain tensioner. 50 is a rotation transmission mechanism. 45 is the sprocket.

Claims (2)

[Claims] (1) Consisting of a rotary table for loading packages to be packaged and a carriage having a film shaft for mounting the film, the carriage is attached to a side body provided on the side of the rotary table, and the carriage has a film shaft mounted on the film shaft. In a stretch wrapping machine that wraps around a packaged item by rotating the packaged item, the shape of the driven vehicle on the rotational surface of the rotating table in the rotation transmission mechanism for driving the rotating table is determined by the rotation of the packaged item. A stretch wrapping machine characterized by having a cross-sectional shape that is approximately similar to that in a plane. (2) It consists of a carriage having a rotary turntable on which the package to be packaged is placed, a film shaft to which the film is attached, and a pre-stretching device installed on the carriage between the film attached to the film shaft and the package to be packaged. In a stretch packaging machine, the carriage is attached to a side body provided on the side of a rotary table, and the film attached to the film shaft is wound around the package by rotation of the package via a pre-stretching device. , characterized in that the shape of the driven vehicle on the rotating surface of the rotary turntable in the rotation transmission mechanism for driving the rotary turntable is approximately similar to the cross-sectional shape of the packaged cargo on the rotation surface. Stretch wrapping machine.